Means for mounting rotatable mixing drums



Nov. 1, 1955 L. G. HILKEMEIER 2,722,408

MEANS FOR MOUNTING ROTATABLE MIXING DRUMS 2 Sheets-Sheet 1 Filed April 21, 1953 fi LOUIS G. HILKEMEIER JNVENTOR.

Nov. 1, 1955 1.. G. HILKEMEIER MEANS FOR MOUNTING ROTATABLE MIXING DRUMS 2 Sheets-Sheet 2 Filed April 21, 1955 LOUIS e. HILKEFIEIER INVENTOR.

FIG.3

United States Patent MEANS FOR MQUNTING :ROTATAZBLE MIXING DRUMS Louis G. Hiikemeier, Plainfield, N.'J., assignorto Worth- .ington Corporation, Harrison, N. J., a corporation of Delaware This invention relates generally to concrete mixing equipment in which a semirigid unit is mounted on a flexible portable unit, and more particularly to means on a truck or transit type mixer for maintaining alignment between the drum track on the rotatable mixer thereof and the rollers in contact with'the drum track.

During the operation of truck or transit type mixers, twisting and Weaving of the chassiswill occurso that considerable distortion exists between the moving component parts such as the drum 'trac'k 'onthe rotatable mixing drum thereof and the rollers on which the drum track is rotatable.

Rigid mounting means for the mixing "drum will prevent alignment between the drum track and the rollers and in addition, are impracticable in that they interfere with the twisting and weaving movement of the frame or chassis of the truck causing severe structural strain 'sueh as disposing all or nearly all of the load on one or the other of the roller members which in turn leads "to increased maintenance and costly breakdowns.

The present invention covers a means for overcoming this problem by providing "a support "on the rearendo'f the frame or chassis of the truck to pivotaily mount inft'he central axis thereof a separate cradle unit haying rollers spaced on either side of the pivotal 'dint in rotatable contact with the drum track of the mixingdruin, and strut members connected at one end to the respective roller brackets for the rollers onthecradle unit and mine other end at, nearly at or in the plane dfthe axis of distortion between the truck frame and'the rotatable mixing drum mounted thereon.

Accordingly, it is an object of the present invention to provide means to allow self-alignment between the rollers and the drum track on the mixing drum of 'a concrete mixer so thatthe load on the rollers will be substantially equally disposed during operation of the -mixer and'undue stresses and strains due to distortion between the mixer and the frame will be "avoided.

It is another object of the present invention to cover an improved manner of rotatably supporting the rear oropen end of the mixing drum 'on 'a truck or transit type mixer having an inclined rotatable mixing drum thereon.

With these and other objects in view, as may appear from the accompanying specification, "the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing a means for mounting rotatable mixing drums of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claims.

In the drawings:

Figure 1 is a diagrammatic sketch of a truck mixer with the support means for the rollers shown in phantomized View.

Figure 2 is an end viewshowing the support means for the rollers. t

Figure 3 is aside view showing the invent-ion.

Figure 4 is a plan view showing the invention.

Patented Nov. 1, 1955 Figure 5 is'a section taken "on the line of Figure 2.

Figure '6'i's a view taken on line 6-6 of Figure 2.

Referring more particularly to the drawings, Figure 1 shows diagrammatically a'preferred form'of the invention -as applied to 'a transit type truck mixer generally designated 1. It will be understood, however, that while "the invention is shown as being applied to a transit type mixer that it is equally applicable to any type of mixing apparatus in which the frame thereof having a mixing drum mounted therein is subject to fiexure during operation. Thus Figure 1 shows the truck mixer 1 having a frame 2'with a rotatable mixing drum 3 of the inclined axis type well known in the art in which the front or closed end is lowermost and is pivotally and rotatably connected by 'means of a self-aligning trunnion bearing 4 to asuitable part of the present invention.

The raised rear end of the mixing drum 3 contains a single charging and discharging opening 8 and is supjported by structure hereinafter described.

Referring 'to Figure 1 again, the longitudinal axis A of the frame 2 is shown therein. Also shown is the axis B of the mixing drum 3 when the drum distorts relative to said frame in a sidewise direction during operation of the truck mixer under conditions which may cause twisting "of the frame '2. When the truck is not in operation "these axes 'fall substantially in the same plane. However, under the effect of twisting the raised rear or open end "of the mixing drum 3 which is a rigid 'or semi-rigid unit, will revolve about "the trunnion bearing 7 'so as 't'o describe a cone or a segment of a cone with the trunnion bearing as its vertex. Theraised or open end of the mixing drum 3 is accordingly supported to reduce this distortion -to a minimum and thus avoid excessive strain and stress on the elements of the mixer.

-Means {for mounting rear or open end of mixing drum The raised rear or open end of the mixing drum 3 has about the outer 'circu'm'f'er'ence thereof near or adjacent to the opening 8, as is shown in Figures 2 and 3 of the drawings, a drum track 9. Contacting the drum track 9 are a pair of spaced rollers 10 and 11 disposed on either side of a cradle generally designated 12, pivotally mount- 'eda'bou't a pivot 13 in the axial line of the mixing drum 3 formed on transverse table member 14 of the cradle and roller support 15 connected to the rear end of the frame 2 transversely of the axis A thereo The transverse table member 14 is disposed at a suitable angle so that the rollers 10 and 11 will initially be in alignment with the drum track '9, all of which is clearly shown in Figures -2 and 3 of the drawings.

Figures 2, 3 and '4 show that the cradle '12 includes the main body member 16 which receives the pivot 13 in the center "thereof 'U-sh'aped brackets 17 and 18 afiixed to the ends of the body portion 16. The brackets 17 and 18 have stub shafts I9 and 20 which rotatably support (the ball or roller type bearings 21 and '22 of the rollers 10 and 1'1 respectively so that the rollers are free to rotate about the respective shafts 19 and 20.

Lubrication means 23 may be provided to lubricate the shafts, if desired.

A resilient pad 24 disposed about the pivot '13 between the transverse table member 14 and the body member '16 of the cradle '12, and s aced resilient pads 25 and 26 on either side of the pivot 13 connected to the upper surface of the transverse table member 14 for contact with the under surface of the body member 12 all act to reduce the shock between the cradle 12 and the cradle and roller support 15, as is clearly shown in Figures 2 and 6 of the drawings.

Fixedly connected to the roller brackets 17 and 18 are L-shaped members 27 and 28. These L-shaped members 27 and 28 each pivotally connect to one end of their respective elongated cylindrical support and alignment struts 29 and 30 by means of pivot pins 31 and 32. The other end of the respective strut members 29 and 30 are disposed to converge inwardly and downwardly underneath the mixing drum 3 towards the front end of the truck frame to a suitable substantially V-shaped strut bracket 33 mounted at or near the axial line of distortion between the truck frame and the rotatable mixer on a transverse channel member 34 disposed transversely of the axis of the frame 2.

Adjustable threaded members 35, 36, 37 and 38 provide means for connecting the struts 29 and 30 to this V-shaped strut bracket 33 and to adjust the strut members to any desired length. The adjustable threaded means 29, 30, 31 and 32 further provide means to initially align the cradle 12 and hence the rollers and 11, and since the length of the struts are fixed by such adjustment the lateral or lineal distortion of the frame will act to rotate, pull or push the cradle 12 to allow the rollers 10 and 11 and the drum track 9 to realign themselves under distortion during operation of the mixer.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. The combination in a concrete mixer having a flexible frame and a rotatable mixing drum of a drum track about one end of said mixing drum and means rotatably supporting said drum track and said mixing drum including, a cradle with spaced rollers thereon in contact with said drum track, a cradle and roller support connected transversely of said frame, said cradle pivotally connected to said cradle and roller support in the longitudinal axis of said frame, and adjustable means connected to said frame substantially on the longitudinal axis thereof and near the axis of distortion between said frame and said mixing drum and to said cradle for continuous self-alignment of said rollers with said drum track during operation.

2. In the combination as claimed in claim 1 wherein said adjustable means includes a strut member for each of said rollers having one end connected to said cradle adjacent said rollers, a bracket mounted on said frame substantially on the axis of distortion of said frame and said mixer, and threaded members on the other end of said struts to connect the same to said bracket in the desired length for alignment of said rollers with said drum track.

3. Means for mounting an inclined rotatable mixing drum with a single end opening on a concrete mixer having a frame subject to flexure during operation thereof including, a drum track about said mixing drum near the open end thereof, a cradle having spaced rollers thereon in contact with said drum track, a cradle and roller support fixedly connected transversely of said frame, said cradle pivotally supported on said cradle and roller support substantially on the longitudinal axis of said frame, and means connected to said cradle and to the frame substantially on the longitudinal axis thereof and near the axis of distortion between said frame and said mixing drum for continuous self-alignment of said rollers with the drum track during operation.

4. Means for mounting an inclined rotatable mixing drum with a single end opening on a concrete mixer having a frame subject to flexure during operation thereof including, a drum track about said mixing drum near the open end thereof, a cradle having spaced rollers thereon in contact with said drum track, a cradle and roller support fixedly connected transversely of said frame, said cradle pivotally supported on said cradle and roller support substantially on the longitudinal axis of said frame, means connected to said cradle and to the frame substantially on the longitudinal axis thereof near the axis of distortion of said frame and said mixing drum for continuous self-alignment of said rollers with the drum track during operation, and means for adjusting said last-mentioned means to the desired length between said cradle and the point of the connection on the frame.

5. Means for mounting an inclined rotatable mixing drum on a concrete mixer having a frame subject to flexure during operation comprising, a drum track about one end of said rotatable mixing drum, a cradle having spaced rollers therein in rolling engagement with said drum track, a cradle and roller support fixedly connected transversely of said frame, said cradle pivotally mounted on said cradle and roller support substantially in the longitudinal axial line of said frame, resilient means between said cradle and cradle support, and adjustable means connected to said cradle and to a point on said frame substantially on the longitudinal axis thereof near the axis of distortion between said frame and the rotatable mixer.

6. Means for mounting an inclined rotatable mixer as claimed in claim 5 wherein said resilient means includes a resilient spacer element between said cradle and the cradle and roller support about the pivot point, and spaced resilient pads connected to the surface of said cradle and roller support for contact with the cradle during operation.

7. Means for mounting the inclined rotatable mixing drum as claimed in claim 4 wherein said adjustable means connected between said cradle and said frame includes, strut members for each of said rollers, one end of said strut members connected to said cradle adjacent said rollers, and the other end of said strut members having threaded adjustment nuts for connecting said other end to the frame.

8. Means for mounting an inclined rotatable mixing drum as claimed in claim 4 wherein said adjusted means includes, a transverse member on said frame provided with a bracket substantially on the longitudinal axis thereof near the axis of distortion between said frame and said mixing drum, and threaded members on said connecting means for adjustably connecting the same to said brackets.

9. Means for mounting an inclined rotatable mixing drum of the single end opening type on a concrete mixer having a frame subject to flexure during operation comprising a drum track about said mixing drum adjacent the end opening, a cradle, roller brackets disposed on either side of said cradle and having rotatable rollers in contact with said drum track, a cradle and roller support mounted on the rear end of said frame transversely of the longitudinal axis thereof, said cradle pivotally mounted on said cradle and roller support in the axial line of said frame, resilient means disposed between said cradle and said support, adjustable means connected between said roller brackets and to said frame on the axial line thereof and near the axis of distortion between said frame and the mixing drum, said adjustable means including strut members for each of said rollers having one end connected to the respective roller bracket, a transverse member on said frame having a strut bracket substantially on the axial line thereof near the axis of distortion between said frame and the mixing drum, and adjustable threaded means on the other end of said struts for connecting them to said brackets in the desired length to initially align said rollers with said drum track.

10. The combination in a transit type mixer including a frame, an inclined rotatable mixing drum with a single rear charging and discharging opening, and a drum track about said mixing drum near said opening of means for rotatably mounting said open end of the mixing drum to allow for misalignment between said frame and said mixing drum during operation of said transit type mixer including, a cradle, spaced roller brackets on either end of said cradle rotatably supporting rollers for rolling contact with said drum track, a cradle and roller support on the rear end of said frame transversely of the axial line of said mixing drum, said cradle pivotally mounted on said cradle and roller support in substantially the axial line of said frame, resilient means disposed between said cradle and the cradle and roller support, strut members for each of said roller brackets and connected to said brackets at one end, adjustable connecting means on the other end of said strut members, a transverse channel member on said frame having a strut bracket thereon near the axial line of distortion between said frame and said mixing drum, said strut members to converge towards said bracket and to be connected thereto in the desired length of initial alignment of said rollers and said drum track by said adjustable connecting means.

11. The combination in a transit type mixer including a frame, an inclined rotatable mixing drum with a single rear charging and discharging opening, and a drum track about said mixing drum near said opening of means for rotatably mounting said open end of the mixing drum to allow for misalignment between said frame and said mixing drum during operation of said transit type mixer including, a cradle, spaced roller brackets on either end of said cradle rotatably supporting rollers for rolling contact with said drum track, a cradle and roller support transversely mounted on the rear end of said frame, the upper surface of said cradle and roller support being disposed at an inclined angle to the horizontal axis of the frame, said cradle pivotally mounted on the upper surface of the said support in the longitudinal axis of said frame, resilient means disposed between said cradle and the cradle and roller support, strut members for each of said roller brackets and connected to said brackets at one end, adjustable connecting means on the other end of said strut members, a transverse channel member on said frame having a strut bracket thereon near the axial line of distortion between said frame and said mixing drum, said strut members to converge towards said bracket and to be connected thereto in the desired length for initial alignment of said rollers and said drum track by said adjustable connecting means.

12. Means for mounting an inclined rotatable mixing drum having a single end opening on a transit type mixer having a frame subject to fiexure during operation thereof comprising, a drum track about the mixing drum adjacent said end opening, a cradle, spaced roller brackets on either end of said cradle rotatably supporting rollers for rolling contact with said drum track, a cradle and roller support fixedly connected transversely of the end of said frame, said cradle pivotally mounted on said cradle and roller support in the longitudinal axis of said frame, resilient means disposed between said cradle and the cradle and roller support, strut members for each of said roller brackets and connected to said brackets at one end, adjustable connecting means on the other end of said strut members, a transverse channel member on said frame having a strut bracket thereon substantially in the axial line of distortion between said frame and said mixing drum, said strut members to converge towards said bracket and to be connected thereto in the desired length for initial alignment of said rollers and said drum track by said adjustable connecting means.

13. Means for mounting an inclined rotatable mixing end opening on a transit type mixer having a frame subject to flexure during operation thereof comprising, a drum track about the mixing drum adjacent said end opening, a cradle, spaced roller brackets on either end of said cradle rotatably supporting rollers for rolling contact with said drum track, a cradle and roller support fixedly connected transversely of the end of said frame, the upper surface of said cradle and roller support being disposed at an inclined angle to the horizontal axis of the frame, said cradle pivotally mounted on said upper surface of the cradle and roller support in the longitudinal axis of said frame, resilient means disposed between said cradle and the cradle and roller support, strut members for each of said roller brackets and connected to said brackets at one end, adjustable connecting means on the other end of said strut members, a transverse channel member on said frame having a strut bracket thereon substantially on the axial line of distortion between said frame and said mixing drum, said strut members to converge towards said bracket and to be connected thereto in the desired length for initial alignment of said rollers and said drum track by said adjustable connecting means.

References Cited in the file of this patent UNITED STATES PATENTS 1,725,682 St. John Aug. 20, 1929 2,589,619 Leef Mar. 18, 1952 2,597,291 Clegg May 20, 1952 FOREIGN PATENTS 126,363 Switzerland May 28, 1927 

